A104652 Numbers k such that 29*k^2 + 29*k +1 = n^2, n sequence = A104651.

0, 32, 3080, 6720, 637032, 60383960, 131735240, 12487111096, 1183646396800, 2582274191000, 244772352350624, 23201836730467360, 50617738823727040, 4798027663264052544, 454802404774267597320, 992208919004971638880, 94050938500074310327912

Offset

1,2

Links

Table of n, a(n) for n=1..17.

Index entries for linear recurrences with constant coefficients, signature (1,0,19602,-19602,0,1,-1).

Formula

a(1)=0, a(2)=32, a(3)=3080, a(4)=19602*a(1)+9800-a(3), a(5)=19602*a(2)+9800-a(2), a(6)=19602*a(3)+9800-a(1), then a(n)=19602*a(n-3)+9800-a(n-6).

G.f.: 8*x^2*(4+381*x+455*x^2+381*x^3+4*x^4) / ( (x-1)*(x^6+19602*x^3-1) ). - R. J. Mathar, Aug 23 2011

Crossrefs

Cf. A104651.

Sequence in context: A113500 A064018 A067321 * A219228 A135787 A016793

Adjacent sequences: A104649 A104650 A104651 * A104653 A104654 A104655

Keyword

nonn,easy

Author

Pierre CAMI, Apr 22 2005

Extensions

More terms from Colin Barker, Apr 16 2014

Status

approved